Piston-connection for indicators and pressure-gages



(N0 Model.)

L. F. LYNE. Pistonflonnectionfor Indicators and Pressure Gages.

'Patent ed Dec. 21,1880.

WTiESSES Z4 N-PETERS, PLOTO-LITHDGRAPHER, WASHINGTON. D. II.

UNrrnn STATES PATENT, @rrrbn.

LEWIS F. LYNE, OF JERSEY CITY, NEW JERSEY.

PISTON-CONNECTION FOR INDICATORS AND PRESSURETGAG ES.

SPECIFICATION formingpart of Letters Patent No. 235,791, dated December21, 1880.

Application filed August 26, 1880. (No model.)

To all whom it may concern.-

Be it known that I, LEWIS F. LYNE, a citizen of the United States,residing in Jersey City, county of Hudson, and State of New Jersey,"have invented certain new and useful Improvements relating toSteam-Engine Indicators, of which the following is a specification.

By the term indicators I include any of the formsof device in which apiston is subjected in a small cylinder to the influence of a spring,and to the action of the steam or vacuum, as the case may be, at one endof the cylinder, for the purpose of moving a pencil or other markingdevice under the influence of the steam and spring, toindicate thepressure in that end of the cylinder at different parts of the stroke.It is usual to mount this in connection with a device for moving a sheetof paper backward and forward with a motion coincident to that of themain piston, and thus to secure an irregularly-marked figure, known as adiagram, which is important in indicating whether the valves of theengine are correctly adjusted.

I have discovered that in the ordinary indicators with the rigidconnection of the spring to the piston, there is a tendency to tilt thepiston in one direction or the other as the spring is much compressed orstretched. This is due to laws relating to the action of coiled springs,which it may not be necessary to investigate. The resultis, that whenthe piston stands perfectly true in the cylinder, when the spring iseasy, a considerable elongation of the spring by a vacuum in thecylinder, or, still more, a great compression of the spring by a highpressure of fluid in the cylinder, tends so strongly to rock or inclinethe piston as to induce serious frictional resistance to the motion. Ihave devised a simple remedy. Imake a universal joint between thecasting to which the spring is connected and the piston. I mount this inthe interior of the piston. No additional space is required. I make thejoint at the mid-height of the piston, so the action is uniform in bothdirections... I obtain avery simple construction by means of aball-joint.

The accompanying drawing forms a part of this specification, andrepresents what I conthe piston.

sider the best means of carrying out the invention. The drawingrepresents the novel parts with so much of the ordinary parts as isnecessary to indicate their relations thereto. The drawing is a centralvertical section through the piston and the means by which the spring isattached thereto.

Referring to the figure and to the letters of reference marked thereon,A is the cylinder of the indicator, B the main body of the piston, and Can ordinary spiral spring of steel wire tempered, or other suitablematerial.

I provide a separate casting, E, finished on its interior to fit tightlyand easily to the ball D, with a sufficient aperture in the bottom toallow the easy passage of the screw-threaded portion D, projectingbelow. Having dropped the pin D D into the casting E, I screw down uponit a tight-fitting plug, E, accurately hollowed on its under side, sothat when it is properly adjusted it allows a free movement upon thepolished sphere D. I use a slot in. the lower end of the pin D D as ameans for operating the pin D by inserting a small screwdriver to screwit down to its proper place in Next the pin D is firmly locked bysetting up on thejam-nut B. Lastly, the screw-plug E is screwed downfirmly to a shoulder, allowing the casting E to tilt freely on the headD.

The exterior of the casting E is screwth readed, and receives acorresponding threaded thimble, E which is equipped with the ordinaryprojections, by which the spring 0 is engaged and firmly united thereto,by solderin g or otherwise, in the ordinary manner. As a result, thespring is strongly engaged, and performs as usual, but with freedom torock itself and its connected casting E in any direction the exigenciesmay require without any appreciable tendency to disturb the verticalposition of the piston B. The neck of the pin D need not be muchcontracted to allow all the rocking which is ever required in practice.The spring exerts its tension and yields in one direction or the other,as required by the widely-varying pressure of the steam under thepiston, with the effect to act directly upward or downward on thepiston, and without any other influence.

B is a pin inserted in the body of the piston and received loosely in ahole in the casting E. It serves to prevent the casting from beingturned around when the spring 0 is put on or taken off. The properconnection for operating the pencil-lever (not shown) is formed byextending upward the head of the screwplug E and applying aproperly-formed cap or nut, E thereon, as indicated in the figure. Allthese parts of the piston, and generally all of the mechanism notrepresented, may be the same as is set forth in the patent to H. TaborDecember 10, 1878, No. 210,643.

The invention is more important on an indicator having a short springbut it may be used with advantage on all indicators Working with apiston and having a spring connected in any manner, so that the actionof the spring or of the connected parts is liable to incline the pistonfrom its proper position in line with the cylinder.

Modifications maybe made in the forms and proportions.

I have made a provision for lubricating the ball-joint by drilling asmall hole directly through the plug E, so that oil supplied to theupper joint will also find its way to the sphere D.

Other means of applying and securing the parts may be adopted.

I claim as my invention 1. As an improvement in steam-engine indicatorsand analogous pressure-gages, the combination of a cylinder, a piston, atensile and contractile spring, and a flexible joint connecting thespring to the piston, so that the spring may accommodate itself byrocking at its point of attachment without tendency to rock the piston,substantially as herein specifiecl.

2. As a piston-connection for indicators, the ball-joint D E E, incombination with the stop or pin B adapted to allow the spring 0 and theconnected parts to rock on the universal joint thus formed withoutliberty to turn horizontally, as herein specified.

3. In combination with the ball-joint D E E, the threaded extension ofthe screw-plug E in the opposite direction, and the threaded cap Eembracing a ball on a connection to the pencil-operating mechanism, allarranged for joint operation, as herein specified.

4c. In a steam-engine indicator, the deep hollow piston B, threaded pinD, ball D, and nut B, in combination with the casting E, pin or stop Bscrew-plug E, cap E spring 0, and thimble E adapted .to serve relativelyto each other and to the cylinder A and a ball-con nection to the pencilmechanism substantially as herein set forth.

In testimony whereof I have hereunto set my hand, at New York city, N.Y., this th day of August, 1880, in the presence of two subscribingWitnesses.

LEWIS F. LYNE.

Witnesses: A EDWD. ORUPLoW,

ERWIN W. THOMPSON.

